Process of making stamping tools



Patented Feb. 25, 1947 oNiTiz-o STATES PATENT OFFICE PROCESS F STAMPING TOOLS i Ward' G- Kifer, Canton, Qliio, assigner t0 The Ti'mken Roller 'Bearing Campaniel Canton,Vv v Ohio, a corporation of Ohio I Y Application November 30, 1.945 SeriaI'No. .631,941

' l 2 Claims.

VThis invention relates to stamping tools for impressing or imprinting identification marks, designs or the like upon articles of manufacture. The object of the present invention is to devise a new process of manufacture by which a large number of stamping tools may be eliciently and economically produced from a single master stamp.

rlhe invention Consists principally inproviding a master .stamp having raised marking ele.- ments thereon, pressing said master stamp rst into engagement with a roughing punch. and then into engagement with a finishing, punCh .to irnpress the marking elements into each of said punches, removing a portion of the marked sur,- 4face of said finishing punch to decrease ythe depression depth of the marks impressed therein, providing a stamp blank having a ridge thereon of greater height than the depth of the impressed marks in said roushing punch, pressing said roughing punch into engagement with said stamp blank to sink said ridges into said stamp blank and to substantially ll the depressed marks in said roughing punch and then pressing said iinishing punch int-o engagement with saidstamp blank to accurately conform the partially formed portions of said ridge to the impressed marks in lsaid finishing punch. The invention also consists in the operations and YQuintinations hereinafter setforth.

In the accompanying drawing wherein like symbols refer to like 'parts wherever they occur,

Figs. 1,' 2, 3, 4 and 5 are sectional views showing the steps in my process or manufacturing stamps,

Fig. 6 is an end elevational View of the stamping end ofthe master stamp,

Fig. '7 is a similar View o f one of the stampsproduced from said master stamp,

Fig. 8 is an enlarged fragmentary sectional view similar to Fig. l,

Fig. 9 is a fragmentary sectional view on the line 9 9 in Fig. 8,

Fig. v10 is an enlarged fragmentary sectional view similar to Fig. 2,

Fig. 11 is an enlarged fragmentary sectional view showing the roughing punch in position'to engage the stamp blank,

Fig. 12 is an enlarged fragmentary section on the line |2-l 2 in Fig. 11,

Fig. 13 is an enlarged fragmentary sectional view similar to Fig. 4,

Fig. 14 is an enlarged fragment-ary sectional view on the line i4- I 4 in Fig. 13,

view showing ,the finishing punch seated en the partially formed letters onthe ,stamp blank; and

Fig, .16 is an enlarged fragmentary sectional view similar to. Fie. .5,

The elements. employed in my process of nroducing stamping tools are a master stamp l, a rougnine punch 2. a iinishing punch 3. and. a stamp blank. 4., all being of cylindrical form for insertion in the central circular opening of a supporting and piloting ring or die 5 adapted to be mounted on a press-bed (not shown) The master stamp I comprises a hardened and finished steel body which is adapted to be secured to a press-ram (not shown) and has raised reverse or negative letters or other marking elements 6 projecting from the bottom surface thereof and arranged in a circle concentric therewith.

The roughing punch 2 is formed from a cylindrical steel slug which is mounted in the ring 5; after which the master stamp is forced downwardly by the press-ram into eng-agement with the upper surface of said slug to form depressed letters 1 therein. The nishing punch 3 is formed in a, similar manner; but has its upper face ground away to reduce the depth of the letters 8 impressed therein. The set of punches 2 and 3 are ground on their lowersurfaces to make them the same height and are then hardened and finished.

The stamp blank 4 is also made of steel and has an upstanding annular ridge 9 onv the upper surface thereof concentric therewith of a diameter corresponding substantially to the diameter of the circular lines of depressed lettering in the roughingand iinishing'punches. lAs'shown in the drawings,l the annular ridge 9 is of substantially greater height than the depth of the depressed letters in the roughing and nishing punches and has a relatively narrow top portion and a relatively wide base portion connected by downwardly diverging sides. The depressed letters in the roughing and finishing dies have relative narrow bottom portions of a width corresponding to the narrow top portion of the ridge on the stamp blank and have downwardly and outwardly diverging sides that are disposed at a greater flaring angle than the side walls of said annular ridge.

In manufacturing a stamping tool, the stamp blank 4 is placed in the supporting and piloting ring 5 with vthe annular ridge 9 disposed uppermost. The roughing punch 2 is then mounted in the ring 5 above the stamp blank 4 therein with the circular series of depressed letters 8 in the bottom of said roughing die member directly Fig. 15 is an enlarged fragmentary sectional 52S above the top of the ridge 9. The roughrlgpllnch 2 is then forced downwardly by the press against the stamp blank 4, thus pressing or sinking the annular ridge 9 thereof downwardly into the body of the stamp blank. At the same time, there is a plastic 110W of the ridge metal which substantially fills the letter impressions 1 in the bottom surface of said roughingrpunch, while the portionsof the ridge outside thel letter area are being forced down substantially iiush with the main surface of the stamp blank. The roughing punch 2 is then removed and replaced with the` finishing punch 3 which is then forced downwardly into Vengagement with the stamp blank 4, the letter forming portions of the annular rib of the stamp blank being further compacted and accurately conformed to the letter impressions 8 due to the shallower depth thereof. The stamp I thus produced is then hardened, without any additional grinding or shaping of the raised let- 2 ters Il thereon.

The hereinbefore stamp manufacturing process has `several important advantages. Several hundred sets of roughing and nishingpunches may be produced with oneV master stamp; and several hundred stamps can be made with each set of roughing and finishing punches.' No guiding means is necessary to aline the depressed'letters of the finishing punch with the partially. formed letters formed'by the roughing punch, as `such alinement is obtained bymerely rotating the finishing punch within the piloting ring until the depressed letters in the bottom of the iinishing punch seat over the partially formed let#- ters formed by the roughing punch. The cutting edges of the raised letters on the finished stamp are as sharp as the cutting edges of the raised letters on the master stamp; andl the metallurgical properties of the finished stamp are superior to those of engraved dies because the structure of the stamp in the area of the letters is compacted by forcing the ridge ofthe stamp blank into the Ybody thereof. 3,

Obviously, VVthe Y hereinbefore described process admits of considerable modicationfwithout departing from Vthe invention. Therefore, I do not wish to Abe limited to the details hereinbefore described.

What I claim is: n

1. The process of manufacturing stamping tools which consists in providing a master stamp having raised marking elements thereon, im pressing the marking elements of the master a stamp blank having a ridge on one face thereof of greater height than the depth of the impressed marks in both punches and located so as to be brought into alinement with said impressed marks,r pressing saidy roughing punch into en, gagement with said stamp blank to sink said ridge into said face of lsaid stamp blank and to lov stamp into a punch blank to form a roughing punch,v impressing the marking elements of said master stamp-into a second punch blank and removing aportion of the marked surface thereof to decrease the depth of the marks impressed therein, and form a finishing punch, providing cause portions of said ridge to substantially ll the impressed marks in said roughing punch and then pressing said finishing punch into engagement with said stamp blank to accurately conformthe partially formed portions of said ridge to the impressedy marks in said finishing punch and to further sink the conformed marks into said face.

2. The process of Vmanufacturing stamping tools which consists in providing a master stamp having raised marking elements arranged in a circle thereon, impressingY the circularly arranged 0 marking elements of the master stamp into a punch blank to form a roughing punch, impressing the marking elements of' said master stamp into a second punch blank and removing a'por: tion of the marked surface thereof to decrease the depression depth of the marks' impressed therein and form a finishingrpunch,l providing a stamp blank having an annular ridge on one face thereof of greater height than the depth of the impressed marks in both punches and located so as to be brought into alinement with said impressed marks, pressing said roughing punch into lengagement with said stamp blank to sink said ridge into said face of saidV stamp blank and to cause portions of said annular ridge to substantially fill the impressed marks in said roughing punch and then pressing said finishing punch into engagement with said stamp blank to accurately conform thepartially formed portions of said annular ridge to the impressed marks in said finishing punch and to further sink the con-v formed marks into said face.

WARD G. KIFER.

' REFERENCES CITED UNITED STATES PATENTS v Number Name Date,

1,247,524. Giebel et al Nov. 20, 1917 Re. 14,835 Giebel et a1. Apr. 6, 1920 1,932,426 Stevens '.Oct. 31', 1933 2,325,989 Tryon Aug. 3, 1943 628,687 y Bradley July 11, 1899 886,331 Richards "Apr, 28, 1908 947,760 Richards Jan. 25,V 1910 1,153,965 Singewald VSept. 21, 1915 

